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Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?

EDIT: in order to save battery life, when not in use, I need to be able to switch everything off (i.e. quiescent). Instead of using the on/off switch for the LM4880s, I thought about disconnecting the split supply with a DPST switch before the regulators. Would that be the best solution? Any idea?

Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?

EDIT: in order to save battery life, when not in use, I need to be able to switch everything off (i.e. quiescent). Instead of using the on/off switch for the LM4880s, I thought about disabling the regulator's enable pins with a DPST switch. That should take care of everything. Would that be the best solution? Any idea?

Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?

Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?

EDIT: in order to save battery life, when not in use, I need to be able to switch everything off (i.e. quiescent). Instead of using the on/off switch for the LM4880s, I thought about disconnecting the split supply with a DPST switch before the regulators. Would that be the best solution? Any idea?

Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?

Here's my idea of a portable headphone amplifier.

A line receiver INA1650 (instrumentation amplifier with all its benefits) that feed two LM4880 that drive the headphones (with separate volume control.)

The power supply would be a split +-2.85V, just below the maximum 6V allowed by the LM4880.

Now my doubts are:

1. The INA1650 requires a minimum of +-2.25V to work, would 2.85V be too little to make it work well?
2. According to the typical application 8.2.5 (INA1650) it has on the tip and ring traces a 100K resistor to ground. Are they really needed? Wouldn't the 500k resistors at the input pins in the chip itself be enough?
3. Is the Cb capacitor still needed at the bypass pin when using the LM4880 with a split supply? 4 I need the total current draw in order to know if the voltage regulator I choose is good enough for the circuit. For each LM4880 ~0.09 A (250mW @ 5.7V per channel) and about 100mA for the INA. Would that be around 300mA for the whole circuit?